The present invention relates to a drain valve which is used to drain condensate from a wet tank used in conjunction with pneumatic braking systems on vehicles such as buses, trucks, truck trailers, trains, construction equipment and large recreational vehicles.
Pneumatic braking systems in vehicles exhibit the condensation of water, oil and other impurities during compression and subsequent cooling of the pressurized air which is employed to actuate air driven pistons for the movement of drums and discs in the braking system. The pressurized air is stored in a plurality of tanks after it has been compressed during which it cools resulting in the condensation of water vapor, oil and other impurities present therein including compressor lubricating oil and gasoline vapor, the vast majority of which condense and collect in the air storage tank immediately connected to the compressor which is known as the "wet tank." The condensate collected in the "wet" tank must be drained periodically to prevent its entrainment into the braking system with the potential for damage to or functional degradation of the system. In the current state of the art, drainage is performed manually by the vehicle driver opening a manually operable, gravity drain valve located at the bottom of the wet tank. Industry standard procedure calls for the driver to drain the wet tank each time the truck's engine is shut-off. There are numerous disadvantages to this prior practice.
Drivers rarely drain the wet tank each time the engine is shut off or even on a regular relatively frequent basis with the result that the braking system is frequently damaged or compromised. This is both dangerous and costly.
Additionally, the manually operated drain valve is frequently located in an inaccessable position beneath the truck which subjects the driver to exposure to grease and dirt. This discourages the driver from draining the wet tank even if he remembers to so do.
It is an object of this present invention to provide a reliable, wet tank drainage system that works automatically in conjunction with a vehicle's ignition system or other electrical system which is periodically energized or de-energized or otherwise generates an electrical signal. This eliminates human inattention and thereby greatly reduces the danger and costs associated with damaging or functionally compromising the braking system.